Broad subcutaneous emphysema with airway obstruction during robot-assisted partial nephrectomy: A case report and literature review

Introduction

Subcutaneous emphysema is a relatively common complication in laparoscopic surgery. However, airway obstruction secondary to subcutaneous emphysema is rare.

Case presentation

A 63-year-old woman with a 56-mm left renal tumor underwent a robot-assisted partial nephrectomy. The operative time was 155 min, the insufflation time was 108 min, and the estimated blood loss was 70 mL. The pneumoperitoneum pressure was maintained at 12 mmHg, except at 15 mmHg for 19 min during tumor resection. The end-tidal CO2 was <47 mmHg throughout the procedure. Postoperatively, broad subcutaneous emphysema from the thigh to the eyelid was observed. Computed tomography revealed airway obstruction, and extubation was aborted. On postoperative day 1, emphysema around the trachea and neck improved and the intubation tube was successfully removed.

Conclusion

Both laryngeal emphysema and physical compression secondary to emphysema can cause airway obstruction. To reduce gas-related complications, the risk of developing subcutaneous emphysema should be properly assessed during robot-assisted laparoscopic surgery.

Temporal trends and patterns in atrial fibrillation incidence: a population-based study of 3.4 million individuals

Background

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia worldwide; confers an increased risk of adverse outcomes and once diagnosed most patients will require lifelong-treatment. Population-based studies of AF incidence are needed to inform health-service planning. However, few reports refer to a standard population and estimates of incidence in high income countries vary by over 12-fold.

Purpose

We aimed to assess trends in the crude and standardised atrial fibrillation incidence by sex, age, socioeconomic status and region in a large general population cohort from England. We also investigated the comorbidity profile of patients over almost two decades.

Methods

We used linked primary and secondary electronic health records of 3.4 million individuals from the Clinical Practice Research Datalink (CPRD). The CPRD database contains anonymised patient data from approximately 7% of the UK population and is broadly representative in terms of age, sex, and ethnicity. Eligible patients aged 16 years and older contributed data between Jan 1 1998 and Dec 31 2017. We defined incident AF diagnosis as the first record of AF in primary care or hospital admission records from any diagnostic position. For incidence calculations, we excluded all individuals who had a diagnosis of AF before the study start date, or within the first 12 months of registration with their general practice. For patients with incident AF, we extracted baseline characteristics, comorbidities, socioeconomic status and geographic region. We calculated standardised rates by applying direct age and sex standardisation to the 2013 European Standard Population. We inferred crude rates by applying year-specific, age-specific and sex-specific incidence to UK census mid-year population estimates.

Results

From 1998 to 2017 AF incidence (standardised by age and sex) increased by 30% (from 247 to 322 per 100,000 person-years; adjusted incidence ratio [IRR] 1.30, 95% CI 1.27–1.33) (Figure 1). Absolute number of incident AF increased by 72% (from 117,880 in 1998 to 202,333 in 2017), due to an increasing number of older people. Comorbidity burden at diagnosis of AF increased (2.58 [SD 1.83] vs 3.74 [2.29] conditions; adjusted difference 1.26, 95% CI 1.14–1.39). Age-standardised incidence was higher in men than women (IRR 1.49; 95% CI 1.46–1.52), and men were younger at diagnosis (adjusted difference 5.53 years; 95% CI 5.36–5.69). Socioeconomically deprived individuals had more comorbidities and were more likely to develop AF than the most affluent individuals (IRR 1.20; 95% CI 1.15–1.24). Over time, the age of AF diagnosis declined disproportionately in the most deprived individuals (Figure 2).

Conclusion

In England AF incidence has increased, and the socioeconomic gradient in age at diagnosis and comorbidity burden widened. This changing burden of AF requires policy-based interventions to prevent associated morbidity and mortality.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation, National Institute of Health Research

Percutaneous coronary intervention on combined VA-ECMO and IMPELLA (ECPELLA) support may reduce myocardial damage in cardiogenic shock patients with STEMI who required mechanical circulatory support

Background

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is an effective therapeutic modality for patients with cardiogenic shock (CS) including STEMI. The VA-ECMO maintains end-organ perfusion, however, it significantly increases damaged left ventricular (LV) afterload. Combined treatment of VA-ECMO and a micro-axial Impella pump, ECPELLA, simultaneously provides systemic circulatory support and LV loading reduction (LV unloading). Studies in ischemic animal models displayed that LV unloading reduced myocardial size. However, it remains unknown whether LV unloading effect by ECPELLA during percutaneous coronary intervention (PCI) can reduce myocardial damage in human STEMI patients with severe cardiogenic shock.

Purpose

This study was to assess whether PCI on ECPELLA support can reduce myocardial damage in STEMI patients with severe cardiogenic shock.

Methods

Sixteen consecutive patients with STEMI and lethal CS (SCAI stage E) were enrolled. All patients suffered from cardiac arrest. Fifteen patients (94%) underwent extracorporeal cardiopulmonary resuscitation using VA-ECMO. From October 2018 to November 2019, PCI was carried out on VA-ECMO support and the mechanical circulatory support (MCS) modality during PCI was switched to ECPELLA since December 2019. There were 8 patients who underwent PCI on ECPELLA support (ECPELLA-PCI) and 8 patients who underwent PCI on single VA-ECMO support (ECMO-PCI). All patients in ECMO-PCI group were escalated to ECPELLA after PCI. Therefore, the difference between groups was timing of LV unloading, i.e., pre-PCI or post-PCI condition. We assessed total MCS flow during PCI, and peak and time course changes in CK-MB levels from days 0 to 3.

Results

There were no significant differences in age, rate of male sex, body surface area, shockable rhythm, serum lactate levels, and door to MCS time. Patients in ECPELLA-PCI had significantly longer door to recanalization time (73min in ECPELLA vs. 49min in VA-ECMO, p&lt;0.05), and higher total MCS flow during PCI (3.1 L/min/sqM vs. 2.0 L/min/sqM, p&lt;0.05). Peak and the area under the curves (AUC) from day 0 to day 3 of CK-MB in ECPELLA-PCI were significantly lower than ECMO-PCI group (peak CK-MB 120 vs. 524 IU/L and CK-MB AUC 143 vs. 464 IU/L*Day, respectively, p&lt;0.05). While all patients received red blood cell (RBC) and plasma (PL) transfusions, ECPELLA-PCI required larger amount of RBC and PL transfusions (p&lt;0.05).

Conclusion

The ECPELLA-PCI appeared to reduce myocardial damage shown by peak and AUC of CK-MB levels. Lager amount of blood transfusion is a major drawback of this treatment modality. Further studies are necessary whether ECPELLA-PCI is an effective revascularization approach for myocardial damage reduction with favorable mid- and long-term outcome in patients with STEMI with severe cardiogenic shock.

Funding Acknowledgement

Type of funding sources: None. Total MCS FLow and Ttoal MCS flow indexPeak CK-MB and CK-MB AUC

Effects of Imprinting and Water Activity on Transesterification and Thermostability with Lipases in Ionic Liquid

The effect of bio-imprinting and water activity on catalytic activities and the thermostability of lipases was investigated for transesterification using vinyl acetate and benzyl alcohol as substrates in ionic liquid, [Cnmim][PF6] (n=4,6,8), and benzene. The catalytic activities were enhanced by imprinting in benzene and [C4mim][PF6], and the relations between the transesterification activities and the water activity in both solvents were approximately bell shaped. The reactivity of the transesterification in benzene was higher than that in [C4<br /> mim][PF6]. The effects of water activity and imprinting on the kinetic parameters in [C4mim][PF6] were examined. Without controlling the water content, the values of Km,VA and Km,BA (Michaelis constants of vinyl acetate and benzyl alcohol, respectively) decreased, and the values of Vm (maximum rate) increased by imprinting. On the other hand, by controlling the water content in the organic media, the values of Vm, Km,VA, and Km,BA increased by imprinting. The activities of lipase in ionic liquid are more strongly affected by water activity and imprinting than those in benzene. We observed effects of water activity on thermostability but none from imprinting.

Association of Education and Depressive Symptoms with Tooth Loss

Previous evidence suggests the association of lower educational attainment and depressive symptoms with tooth loss. The hypothesis of this study was that these factors may exacerbate the effect on tooth loss beyond the sum of their individual effects. We aimed to clarify the independent and interactive effects of educational attainment and depressive symptoms on the number of missing teeth among community residents. Cross-sectional data of 9,647 individuals were collected from the general Japanese population. Dental examination was conducted by dentists. Educational attainment was categorized into 3 levels based on the number of educational years: ≤9, >9 to ≤12, and >12 y. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depressive symptoms; a total score of ≥16 and/or the use of medications for depression indicate the presence of depressive symptoms. In the multivariate analysis with adjustment for conventional risk factors, educational attainment was identified as a determinant of the number of missing teeth (>9 to ≤12 y of education: coefficient = 0.199, 95% confidence interval [CI], 0.135 to 0.263, P < 0.001; ≤9 y of education: coefficient = 0.318, 95% CI, 0.231 to 0.405, P < 0.001: reference, >12 y of education). An analysis that included interaction terms revealed that the relationship between "≤9 y of education" and the number of missing teeth differed depending on the depressive symptoms, indicating a positive interactive association (coefficient for interaction = 0.198; 95% CI, 0.033 to 0.364, P for interaction = 0.019: reference, >12 y of education). Our study suggests the presence of a significant association between educational attainment and tooth loss, as well as a partial interactive association between "≤9 y of education" and "depressive symptoms" in the general Japanese population.

Effect of eicosapentaenoic acid/docosahexaenoic acid on coronary high-intensity plaques detected with non-contrast T1-weighted imaging: subgroup analysis of the AQUAMARINE EPA/DHA study

Background

In the recent the Reduction of Cardiovascular Events with EPA-Intervention Trial (REDUCE-IT), statin therapy plus high-dose eicosapentaenoic acid (EPA) significantly reduced the risk of cardiovascular death in patients with coronary artery disease (CAD) with elevated triglyceride (TG) levels. An epidemiologic study has shown that increasing the intake of long-chain n-3 polyunsaturated fatty acids, especially EPA and docosahexaenoic acid (DHA), are associated with a lower risk of fatal CAD. However, the anti-atherosclerotic effect of high-dose EPA/DHA has not be clarified.

We reported that coronary high-intensity plaques (HIPs) detected with non-contrast T1-weighted imaging (T1WI) on cardiac magnetic resonance (CMR), which can be uniquely quantitative assessed using the plaque-to-myocardium signal intensity ratio (PMR) of ≥1.4, are significantly associated with future coronary events. Moreover, we demonstrated that intensive statin therapy reduces the PMR of coronary HIPs by 19% but is unlikely to completely resolve HIP (PMR&lt;1.0).

In the AQUAMARINE EPA/DHA study, our goal was to assess the anti-atherogenic effect of EPA/DHA in an exploratory manner by examining the change in PMR of coronary HIPs after 12 months of EPA/DHA therapy in patients with CAD on statin therapy.

Methods

This study was designed as a single-center, triple-arm, parallel-group, randomized controlled, open-label, superiority trial examining the effect of 12 months of additional EPA/DHA therapy on coronary HIPs in patients with CAD who receiving statin therapy. Eligible subjects are randomly assigned to the 2 g/day EPA/DHA group (n=26), the 4 g/day group (n=23), or the no EPA/DHA (statin-only) group (n=24) between May 2014 and December 2017. The PMR was defined as the signal intensity of the coronary plaque divided by that of nearby left ventricular myocardium. The primary endpoint is the change in PMR after EPA/DHA treatment.

Results

These 3 groups were well matched at baseline, with no statistically significant differences in age, male sex, conventional coronary risk factors, TG level, medications, and PMR. Figure 1 shows subgroup analysis of patients with high triglyceride levels (&gt;150mg/dl). In the patient-based analysis (A), 12 months of EPA/DHA therapy significantly reduced the PMR of primary lesions. In the segment-based analysis (B), additional reduction of PMR was observed in the high-dose EPA/DHA group compared with the no EPA/DHA treatment group.

Discussion

The present study of patients with high triglyceride levels demonstrated that EPA/DHA had a dose-dependent anti-atherosclerotic effect. This finding may provide additional information of EPA/DHA for lowering the residual risk in patients with CAD on statin therapy.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Takeda Pharmaceutical Co., Ltd.

Combined use of VA-ECMO and IMPELLA (ECPELLA) as a possible strategy to improve outcomes in patients who underwent E-CPR

Background

Extracorporeal Cardio-Pulmonary Resuscitation (E-CPR) is an effective tool for patients with refractory cardiac arrest (CA). Since VA-ECMO provides strong afterload, IABP is often used to increase left ventricular load. Recently, in Japan, the effectiveness of VA-ECMO in combination with IMPELLA, a forward flow mechanical circulatory support device (ECPELLA) is gaining attention.

Purpose

We investigated usefulness of ECPELLA in patients with refractory CA.

Method

We reviewed 133 patients that had E-CPR from January 2012 through January 2020 {mean age: 67±15 years, male 65%, Out of hospital Cardiac Arrest (OHCA) 35%, Acute coronary Syndrome (ACS) 54%}. We divided these patients into ECMO with IMPELLA (ECPELLA group), ECMO with IABP (IABP group) and ECMO alone (ECMO alone group). The primary endpoint is 30-day survival and good neurological prognosis defined as CPC (cerebral performance categories) 1 or 2.

Result

During the study period, of the 133 patients, there were 20 in the ECPELLA group, 78 in the IABP group, 35 in the ECMO alone group. There were no significant differences in age in all three groups. There were more males, shockable rhythm, OHCA and ACS in the ECPELLA and IABP groups compared to the ECMO alone group. But there was no significant difference between the ECPELLA and IABP groups. Compared with other groups, ECPELLA had the shortest time from cardiac arrest to ECMO placement. Regarding endpoints, the rate of 30-day survival and favorable neurological prognosis were higher in the ECPELLA group, followed by the IABP group and then the ECMO alone group. (ECPELLA: 55% vs. IABP: 23% vs. ECMO alone: 9%; P=0.0009, ECPELLA: 35% vs. IABP: 13% vs. ECMO alone: 9%; P=0.04) Next, Kaplan Meier analysis was performed to analyze 30-day all-cause mortality. The ECPELLA group had a significantly higher survival rate (P=0.01 by log-rank test). Multivariate cox proportional hazard analysis including the age, OHCA, shockable rhythm, ACS, Collapse-to-ECMO under 60 min revealed that the age (hazard ratio [HR], 1.28 (10 years increase), 95% confidence interval [CI], 1.08–1.53, P=0.004) and Collapse-to-ECMO under 60 min (HR, 0.37, 95% CI, 0.21–0.68, P=0.001) or ECPELLA (HR, 0.46, 95% CI, 0.20–0.694, P=0.03) were significantly associated with mortality.

Conclusion

ECPELLA used with E-CPR is an effective tool to improve mortality and neurologic status.

Funding Acknowledgement

Type of funding source: None

Characterization of thromboembolic and bleeding risks in cancer patients with acute myocardial infarction under the use of guideline-recommended dual-antiplatelet therapy

Background

Atherosclerotic cardiovascular disease including acute myocardial infarction (AMI) has become one of major co-existing diseases in cancer patients due to their improved survival rate. Current guideline recommends dual-antiplatelet therapy (DAPT) in patients with AMI. Given that the presence of cancer elevates not only coagulability but bleeding risks, these substrate may further worsen cardiovascular outcomes and bleeding risks in cancer subjects with AMI receiving DAPT.

Methods

We retrospectively analyzed 712 AMI patients treated by primary PCI with drug-eluting stent and DAPT between 2007 and 2017. The diagnosis of cancer was determined through medical record review. Clinical characteristics, thromboembolic (=all-cause death+non-fatal MI+stroke) and bleeding events were compared in AMI subjects with vs. without cancer.

Results

Cancer was identified in 11.1% (=79/712) of study subjects. Of these, around 40% of them had gastrointestinal cancer (=35/79), followed by lung cancer (=5/79) and breast cancer (=8/79). Cancer patients were more likely to be older (77±7 v. 69±13 years, p&lt;0.001) with a history of Af (25 v. 10%, p&lt;0.001), CKD (eGFR&lt;60: 60 v. 42%, p=0.002), anemia (hemoglobin: 12.8±1.8 v. 13.9±1.8 g/dl, p&lt;0.001). Under anti-thrombotic (DAPT=86%, triple-antiplatelet therapy=14%) and optimal medical therapies (ACE-I=90%, beta-blocker=76%, statin=96%), more frequent occurrence of thromboembolic events was observed in patients with cancer (34.2 v. 12.6%, p=0.004, Picture). Furthermore, the presence of cancer was associated with more than four times greater risk of bleeding events compared to non-cancer subjects (18.9 v. 4.3%, p&lt;0.001, Picture). In particular, the frequency of both major (10.1 vs. 3.3%, p=0.003) and minor (8.9 vs. 0.9%, p&lt;0.001) bleeding events was significantly higher in patients with cancer. In multivariate analysis, cancer independently predicted bleeding events (Table).

Conclusions

Under the use of guideline recommended DAPT, the concomitance of cancer in AMI subjects was a predictor for thromboembolic as well as bleeding events. In particular, the relationship between cancer and bleeding was significant. These observations underscore the appropriate selection and duration of anti-thrombotic agents in AMI subjects with cancer.

Cardiac/Bleeding Events in AMI Subjects

Funding Acknowledgement

Type of funding source: None

NRSF-GNAO1-CaMK2 axis exacerbates cardiac remodeling and progresses heart failure by impairing Ca2+ homeostasis

Background

In the development of heart failure, pathological intracellular signaling reactivates fetal cardiac genes, which leads to maladaptive remodeling and cardiac dysfunction. We previously reported that a transcriptional repressor, neuron restrictive silencer factor (NRSF) represses fetal cardiac genes and maintains normal cardiac function under normal conditions, while hypertrophic stimuli de-repress this NRSF mediated repression via activation of CaMKII. Molecular mechanisms by which NRSF maintains cardiac systolic function remains to be determined, however.

Purpose

To elucidate how NRSF maintains normal cardiac homeostasis and identify the novel therapeutic targets for heart failure.

Methods and results

We generated cardiac-specific NRSF knockout mice (NRSF cKO), and found that these NRSF cKO showed cardiac dysfunction and premature deaths accompanied with lethal arrhythmias, as was observed in our previously reported cardiac-specific dominant-negative mutant of NRSF transgenic mice (dnNRSF-Tg).

By cDNA microarray analysis of dnNRSF-Tg and NRSF-cKO, we identified that expression of Gnao1 gene encoding Gαo, a member of inhibitory G proteins, was commonly increased in ventricles of both types of mice.

ChIP-seq analysis, reporter assay and electrophoretic mobility shift assay identified that NRSF transcriptionally regulates Gnao1 gene expression.

Genetic Knockdown of Gαo in dnNRSF-Tg and NRSF-cKO by crossing these mice with Gnao1 knockout mice ameliorated the reduced systolic function, increased arrhythmogenicity and reduced survival rates.

Transgenic mice expressing a human GNAO1 in their hearts (GNAO1-Tg) showed progressive cardiac dysfunction with cardiac dilation. Ventricles obtained from GNAO1-Tg have increased phosphorylation level of CaMKII and increased expression level of endogenous mouse Gnao1 gene. These data suggest that increased cardiac expression of Gαo is sufficient to induce pathological Ca2+-dependent signaling and cardiac dysfunction, and that Gαo forms a positive regulatory circuit with CaMKII and NRSF.

Electrophysiological analysis in ventricular myocytes of dnNRSF-Tg revealed that impaired Ca2+ handling via alterations in localized L-type calcium channel (LTCC) activities; decreased T-tubular and increased surface sarcolemmal LTCC activities, underlies Gαo-mediated cardiac dysfunction.

Furthermore, we also identified increased expression of Gαo in ventricles of two different heart failure mice models, mice with transverse aortic constriction and mice carrying a mutant cardiac troponin T, and confirmed that genetic reduction of Gαo prevented the progression of cardiac dysfunction in both types of mice.

Conclusions

Increased expression of Gαo, induced by attenuation of NRSF-mediated repression forms a pathological circuit via activation of CaMKII. This circuit exacerbates cardiac remodeling and progresses heart failure by impairing Ca2+ homeostasis. Gαo is a potential therapeutic target for heart failure.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grants-in –Aid for Scientific Research from the Japan Society for the Promotion of Science

Characterization of plaque features exhibiting physiological mismatch between fractional flow reserve and resting index: near-infrared spectroscopy imaging analysis

Background

In addition to fractional flow reserve (FFR), resting indexes (RI) have been shown as another physiological measure to evaluate myocardial ischemia. Despite the clinical usefulness of RI without the use of intravenous vasodilatory agent, discrepancy between FFR and RI infrequently occurs. Whether this physiological mismatch is derived by specific plaque feature remains unknown.

Purpose

To characterize coronary plaques associated with coronary physiological mismatch.

Methods

We analyzed 59 coronary arteries (LAD/RCA/LCX=49/4/6) with FFR≤0.80 in 57 stable CAD subjects receiving PCI. Following measurement of FFR and RI, culprit lesion was evaluated by near-infrared spectroscopy and intravascular ultrasound (NIRS/IVUS). The analyzed vessels were stratified according to FFR and RI values: FFR≤0.75+RI&gt;0.89 (n=6: physiological mismatch), FFR&gt;0.75+RI&gt;0.89 (n=6), FFR≤0.75+RI≤0.89 (n=33) and FFR&gt;0.75+RI≤0.89 (n=14).

Results

The median values of percent diameter stenosis, FFR and RI were 51%, 0.75 and 0.87, respectively. Physiological mismatch was observed in 10.1% (=6/59) of analyzed vessels. On IVUS imaging, maximum percent plaque area was greater than 70% in all groups (p=0.29). Furthermore, there were no significant differences in angiographic and IVUS-derived minimum lumen area across 4 groups (Table). However, culprit lesions exhibiting physiological mismatch contained a substantially larger amount of lipid plaque, reflected by a higher maximum 4-mm lipid-core burned index (maxLCBI4mm: p=0.04) on NIRS imaging (Table). Multivariate analysis demonstrated maxLCBI4mm as the only plaque feature associated with physiological mismatch (odds ratio=1.010, 95% CI: 1.001–1.019, p=0.02).

Conclusion

Plaque feature associated with coronary physiological mismatch was the extent of lipidic materials but not the quantity of coronary atheroma. Since the accumulation of lipidic plaque component is caused by endothelial dysfunction, this vascular substrate could impair baseline vasomotion, thereby causing a lower FFR despite preserved RI value. Evaluation of lipidic burden may be a potential option to avoid unnecessary deferral of revascularization in subjects with normal RI value.

maxLCBI4mm in each group

Funding Acknowledgement

Type of funding source: None

P5635Predictive ability of lipdic burden for FFR-derived physiological measures: insights from near-infrared spectroscopy imaging analysis

Background

Fractional flow reserve (FFR) has enabled to physiologically assess the myocardial ischemia of coronary artery with intermediate stenosis. Mechanistically, not only the severity of coronary stenosis but also the extent of maximal vasodilatation within the entire coronary artery potentially affects this physiological measure. Since the accumulation of lipidic materials within vessel wall increases vascular stiffness via inducing endothelial dysfunction, the presence of lipidic atheroma burden may affect physiological measures.

Purpose

To investigate the association of FFR with lipidic coronary atheroma by near-infrared spectroscopy/intravascular ultrasound (NIRS/IVUS) imaging, which quantitatively visualize lipidic burden in vivo.

Methods

We analyzed 61 coronary arteries (LAD/RCA/LCX=52/5/4) with FFR≤0.80 in 59 stable coronary artery disease subjects receiving PCI. Following FFR measurement, NIRS/IVUS imaging was conducted to evaluate the extent of atheroma burden (maximum percent plaque area=max%PA) and lipidic materials (lipid core burden index within the entire vessel=LCBIvessel). The analyzed vessels were stratified according to FFR: definite FFR group (FFR≤0.74, n=34) and gray-zone FFR group (0.75≤FFR≤0.80, n=27).

Results

NIRS/IVUS imaging analysis (analyzed longitudinal length=77±7mm) was more likely to exhibit a significantly higher LCBIvessel and a larger max%PA in the definite FFR group (Table). Of note, FFR was significantly correlated to LCBIvessel (ρ=-0.299, p=0.02), but not max%PA (ρ=-0.255, p=0.07). Multivariate analysis demonstrated that an independent determinant of FFR≤0.74 was LCBIvessel [odds ratio (OR)=1.016, 95% confidential interval (CI)=1.002–1.031, p=0.02], but not max%PA [OR=1.084, 95% CI=0.994–1.182, p=0.07]. Area under the receiver-operating characteristic curve analysis elucidated that the addition of LCBIvessel to angiography- and IVUS-derived measures resulted in a significant improvement for detecting FFR≤0.74 (picture).

Definite FFR Group (FFR≤0.74, n=34) Gray-zone FFR Group (0.75≤FFR≤0.80, n=27) p value Fractional flow reserve (FFR) 0.68±0.05 0.78±0.02 <0.01 Percent diameter stenosis (%) 56.2±13.1 51.9±7.8 0.16 Maximum percent plaque area (max%PA, %) 84.3±6.9 79.9±7.2 0.01 Lipid core burden index within the entire vessel (LCBIvessel) 102.0±60.2 65.6±51.6 0.01

ROC analysis for detecting FFR≦0.74

Conclusion

The propagation of lipidic burden associates with the physiological measures. The present findings indicate the possibility that vessel characteristics or instability may have influence for causing ischemia on the coronary artery.

P5480Impact of Silent Myocardial Ischemia on One Year Mortality after Successful Coronary Intervention: Data from Japanese Multicenter (KICS) Registry

Introduction

Under the awareness of appropriate use criteria, the significance of PCI for the patients with silent myocardial ischemia (SMI) decreases. On the other hand, the prognoses of SMI patients have been reported to be equivalent to those of symptomatic effort angina pectoris (EAP) patients. We aimed to clarify the prognosis of SMI after PCI and elucidate the factors influencing the mortality.

Methods

The Kumamoto Intervention Conference Study is multicenter registry enrolling consecutive patients undergoing PCI in 16 centers in Japan. Overall, 17,688 consecutive patients were enrolled during April 2008 to March 2017. To compare the clinical events between SMI and EAP, 8,278 subjects, excluding acute coronary syndrome, post successful PCI were enrolled with 1-year follow-up data.

Results

In this study, 2,071 patients were classified as SMI and 6,207 patients were EAP. Male, lower body mass index (BMI), diabetes, chronic kidney disease (CKD), smoking habits, prior myocardial infarction (MI), composite of cerebrovascular disease and composite of peripheral arterial disease were all significantly higher in the SMI group. Although nonfatal MI and stent thrombosisduring 12-monthswere comparable between the 2 groups, all-cause mortality and cardiac death during 12-months were significantly higher in the SMI group than in the EAP group (3.9% vs 1.8%, p<0.001, 1.4% vs 0.5%, p<0.001, respectively). On the other hand, Repeat Revascularization rate during 12-months was significantly lower in the SMI group than in the EAP group (15.7% vs 19.5%, p<0.001).Kaplan-Meier analysis for cardiac death showed a significant difference between the 2 groups (Figure). In a multiple logistic regression analysis, in addition to lower BMI and CKD, SMI was an independent predictor for cardiac death. Even after adjustment by propensity-score matching with predictive factors for cardiac event, SMI showed a higher cardiac death rate compared with EAP (1.4% vs 0.5%, p=0.004), and it remained as a significant predictor.

Conclusion

In this study, SMI itself was associated with higher mortality after PCI. Strict follow-up and assessment of residual ischemia should be necessary for SMI patients.

P1561An elevated risk of heart failure and stroke events in octogenarian Japanese patients with acute myocardial infarction who received percutaneous coronary intervention

Background

The proportion of the octogenarian population is expanding especially in Eastern society. Due to the clustering of risk factors, acute myocardial infarction (AMI) represents a major cardiovascular complication in octogenarian subjects. This suggests the need to further optimize their therapeutic management to prevent future cardiac events after AMI. However, analysis of clinical characteristics and cardiovascular outcomes in octogenarian subjects with AMI who received the current established medical therapies is limited.

Purpose

To investigate clinical features and prognosis in octogenarian AMI subjects treated with percutaneous coronary intervention (PCI).

Methods

We analyzed 1547 AMI subjects underwent PCI between 2007 and 2017. Baseline characteristics and the occurrence of composite major adverse cardiovascular events (cardiac death, non-fatal MI, revascularization, heart failure and stroke) were compared in octogenarian and non-octogenarian subjects.

Results

22.0% (340/1547) of study subjects was octogenarian. They were more likely to have chronic kidney disease (CKD) and a lower level of LDL-C on admission (Table). Moreover, a higher prevalence of severer Killip class and LVEF <30% were observed in octogenarians (Table). However, they were not optimally treated with the established medical therapies at discharge (Table). During the observational period (median=3.1 years), the composite of cardiovascular events more frequently occurred in octogenarian subjects. Of note, they exhibited a 2.15-fold and 3.01-fold increased risk for heart failure and stroke events, respectively (Figure).

Table 1 Non-Octogenarian (n=1207) Octogenarian (n=340) P-value CKD* (%) 33.8 63.2 <0.0001 LVEF <30% (%) 5.7 10.3 0.02 Killip class 1.33±0.03 1.55±0.05 <0.0001 LDL-C (mmol/L) 3.20±0.03 2.80±0.05 <0.0001 Statin (%) 86.3 78.2 0.0006 Beta-blocker (%) 74.0 65.8 0.005 ACE-I/ARB (%) 87.3 76.6 <0.0001 DAPT (%) 86.0 88.6 0.42 *CKD is defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2.

Figure 1

Conclusions

Octogenarian subjects with AMI were high-risk group associated with heart failure and stroke events. Their distinct clinical backgrounds may affect the adoption of optimal medical therapies, potentially resulting in worse cardiovascular outcomes. Further intensified management should be applied to octogenarian subjects with AMI.

P5502Comparison of clinical characteristics and prognosis between non-octogenarians and octogenarians with cardiac troponin positive acute myocardial infarction

Background

Cardiac troponin (cTn) is the preferred biomarker for the diagnosis of acute myocardial infarction (AMI). Octogenarians who presented cTn positive AMI are not usually recruited in clinical trials. Therefore, their clinical characteristics and prognosis are rarely investigated.

Objective

To study the characteristics and prognosis in octogenarians who presented cTn positive AMI.

Methods and results

The Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET) is a prospective and multicenter registry. A total of 3,283 consecutive AMI patients who were diagnosed by cTn-based criteria were included. The patients were divided into non-octogenarians (n=2,593) and octogenarians (n=690). Compared with non- octogenarians, octogenarians showed significantly lower incidence of diabetes mellitus (37.6% and 31.9%, p=0.006) and dyslipidemia (53.6% and 45.6%, p<0.001), and significantly higher incidence of hypertension (64.1% and 75.3%, p<0.001) and chronic kidney disease (38.7% and 68.7%, p<0.001). Octogenarians showed significantly longer onset to door time (p<0.001) and longer door to device time (p<0.001). Though, compared with non-octogenarians, octogenarians showed lower peak CK (2,506 and 1,926, p<0.001), LVEF was significantly lower in octogenarians (54.6% and 52.6%, p=0.005). The presentation of AMI was different between the two group. The incidence of ST-segment elevation MI (STEMI) was 70.7% in non-octogenarians and 62.0% in octogenarians. Non-STEMI with CK elevation and without CK elevation were 16.2% and 13.1% in non- octogenarians, and 20.9% and 17.1% in octogenarians. In-hospital mortality was higher in octogenarians (4.7% and 13.2%, P<0.001). Especially, octogenarians with STEMI and non-STEMI with CK elevation showed the highest in-hospital mortality. And octogenarians without CK elevation showed similar in hospital mortality with non-octogenarians with STEMI (Figure).

Conclusions

J-MINUET showed the poor prognosis of octogenarians who were diagnosed as AMI based on cTn.

Acknowledgement/Funding

None

6131Association between hospital care quality and readmission among Japanese patients with heart failure. From JROAD-DPC study

Background

Measuring the process of care has become a widely used practice to improve a quality of care. Recently, some studies have demonstrated poor to no correlation between 30-day readmission rates and quality of care for heart failure (HF) among hospitalized HF patients. However the investigation about relationships of care quality for HF and 1 year outcome is limited.

Purpose

To investigate the relationship between quality of care in each hospitals and readmission among HF patients in Japan.

Methods

From Japanese Registry of All cardiac and vascular diseases (JROAD-DPC) database in 2014, 84,325 HF patients hospitalized to 741 certificated hospitals by Japanese Circulation Society were analyzed. A primary endpoint was readmission for HF in one year. Five performance measures were defined as prescription rate of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB), prescription rate of beta blocker and prescription rate of spironolactone, measurement rate of echocardiography and measurement rate of B-type natriuretic peptide (BNP) during hospitalization. For each of the five measures, a composite score was created by giving points ranging from 1 to 4 from the lower quartile of rates, with the score ranging from 5 to 20 points. Hazard ratios (HR) indicating the effects of the performance measures were estimated using Cox proportional hazard models. Covariates included age, gender, Charson score, and NYHA class.

Results

In Japanese HF patients (age; 78.1 years old, man 52%), the HF readmission rate in one year was 14,520 (17.2%). The readmission rate decreased with higher quartiles of prescription rate in each medications and performance rates. The highest quartile of each measurements was significantly lower risk for readmission compared to the lowest quartile (ACE/ARB, adjusted HR 0.87 [95% CI, 0.83–0.91], p<0.001; beta-blocker, 0.83 [0.79–0.88], p<0.001; spironolactone, 0.88 [0.83–0.92], p<0.001; echocardiography, 0.90 [0.86–0.94], p<0.001; BNP, 0.92 [0.87–0.96], p<0.001). Kaplan-Meier curves showed that readmission rates were better among higher composite score, compared to lower composite score (Log-rank test=p<0.001). (Figure) Higher composite scores were associated with statistically significant risk reduction of 23% for HF readmission (HR 0.77, 95% CI [0.73–0.81], p<0.001).

Figure 1

Conclusion

The hospital performance measures were associated with a significant risk reduction of readmission in Japanese patients with HF.

P3392Potential of imaging-guided PCI for event suppression in Japanese acute myocardial infarction patients: J-MINUET substudy

Background

Intravascular ultrasound (IVUS) and Optical Coherence Tomography (OCT) has been widely used in clinical settings. Although favorable results of imaging-guided percutaneous coronary intervention (PCI) compared with angio-guided PCI were observed in several studies, impacts of institutional-based usage frequency, about imaging-guided PCI, have not been well elucidated.

Methods

To elucidate the impact of imaging-guided PCI and the effects of frequency of its usage, we analyzed data of the Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET). This was a prospective and multicenter registry consisting of 3,283 AMI patients, who were hospitalized within 48 hours of onset from July 2012 to March 2014. Clinical follow-up data was obtained for 3 years. In this sub-study, a total of 2,788 patients who underwent urgent PCI having detailed procedural information were enrolled. We analyzed the differences of utilization rates of imaging-guided PCI among the participating institutions and the impacts for the clinical events. The participating institutions were divided into 3 groups by the frequency of IVUS usage: low frequency institutions: under 50%; moderate frequency institutions: 50% to 90%; and, high frequency institutions: over 90%.

Results

In this cohort registry, patients were enrolled from 28 institutions. The utilization rate of coronary imaging varied widely depending on each institution from 15.4% to 100% (mean 85.7%±24.3, median 97.4%). When the institutions were divided into 3 groups by the frequency of intravascular imaging usage, four low frequency institutions enrolled 295 patients, five moderate frequency institutions enrolled 624 patients, and 19 high frequency institutions enrolled 1,491 patients. Although the incidence of MACE (death, MI, stroke, cardiac failure, or revascularization for unstable angina) decreased stepwise (33.2%, 23.7%, and 19.7%) (gray bar in the Figure), the event rates of the imaging-guided PCI cases among the 3 groups were comparable (21.6%, 21.9%, and 19.6%) (white bar in the Figure). On the other hand, a gradual event reduction between the 3 groups was observed in the angio-guided PCI cases (black bar in the Figure). In comparison of MACE rate between imaging-guided and angio-guided PCI, there were statistically significant differences in the low frequency and moderate frequency institutions (p=0.001 and p=0.012, respectively). In contrast, comparable event rates were observed in the high frequency institutions (p=0.441).

MACE rate by imaging usage frequency

Conclusions

In Japanese ACS patients treated with imaging-guided PCI, better suppression of clinical events during 3-year was found in the institutions with the more frequent use of intravascular imaging, mainly due to stepwise event suppression in the cases of angio-guided PCI. On the other hand, the clinical benefit of coronary imaging was obtained independently of the frequency of use and its experience.

4968Increased Gao expression underlies cardiac dysfunction and lethal arrhythmias accompanied with abnormal Ca2+ handling

Background

We previously demonstrated that a transcriptional repressor, neuron restrictive silencer factor (NRSF), maintains normal cardiac function and electrical stability. Transgenic mice expressing a dominant-negative mutant of NRSF in their hearts (dnNRSF-Tg) exhibit systolic dysfunction with cardiac dilation and premature death due to lethal arrhythmias like human dilated cardiomyopathy (DCM). Underlining mechanisms remain to be elucidated, however.

Purpose

We studied underling mechanisms by which NRSF maintains normal cardiac function to identify novel therapeutic targets for heart failure.

Methods and results

We generated cardiac-specific NRSF knockout mice (NRSFcKO) and confirmed that cardiac phenotypes of NRSFcKO are similar to those of dnNRSF-Tg.

cDNA microarray analysis revealed that cardiac gene expression of GNAO1 that encodes Gαo, a member of inhibitory G protein Gαi family, is increased in both dnNRSF-Tg and NRSFcKO ventricles.

We confirmed that GNAO1 is a direct target of NRSF through ChIP-seq analysis, reporter assay and electrophoretic mobility shift assay.

In dnNRSF-Tg, pharmacological inhibition of Gαo with pertussis toxin improved systolic dysfunction and knockdown of Gαo by crossing with GNAO1 knockout mice improved not only systolic function but also frequency of ventricular arrhythmias and survival rates.

Electrophysiological and biochemical analysis in ventricular myocytes obtained from dnNRSF-Tg demonstrated that genetic reduction of Gαo ameliorated abnormalities in Ca2+ handling, which include increased current density in surface sarcolemmal L-type Ca2+ channel, reduced content of sarcoplasmic reticulum Ca2+ and lowered peak of Ca2+ transient. Furthermore, genetic reduction of Gαo attenuated increased phosphorylation levels of CAMKII in dnNRSF-Tg ventricles, which presumably underlies the improvement in Ca2+ handling. In addition, we identified increased Gαo expression in ventricles of heart failure model mice induced by transverse aortic constriction and cardiac troponin T mutant DCM model mice, in both of which, genetic reduction of Gαo ameliorated cardiac dysfunction.

Figure 1

Conclusions

We found that increased expression of Gαo, induced by attenuation of NRSF-mediated repression, plays a crucial role in the progression of cardiac dysfunction and lethal arrhythmias by evoking Ca2+ handling abnormality. These data demonstrate that Gαo is a potential therapeutic target for heart failure.

P1954Prognostic value of the CHADS2 score for adverse cardiovascular events in acute myocardial infarction patients without atrial fibrillation: J-MINUET Substudy

Background

The CHADS2score has mainly been used to predict the likelihood of cerebrovascular accidents in patients with atrial fibrillation. However, increasing attention is being paid to this scoring system for risk stratification of patients with coronary artery disease. We investigated the value of the CHADS2 score in predicting cardiovascular events in Japanese acute myocardial infarction (AMI) patients without atrial fibrillation.

Methods

To elucidate the prognostic value of CHADS2score in AMI patients, we analysed data of the Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET). This was a prospective and multicenter registry consisting of 3,283 AMI patients, who were hospitalized within 48-hours of onset from July 2012 to March 2014. We calculated the CHADS2 scores for 3,044 patients without clinical evidence of atrial fibrillation. The presence of heart failure was substituted by Killip classification>2 on admission. Clinical follow-up data was obtained for 3 years. In addition to the in-hospital mortality,we evaluated cardiovascular events, defined as all cause deathor non-fatal MI during 3-year follow up periods.

Results

In this study, enrolled patients were classified into low- (point 0–1), intermediate- (point 2–3), and high-score (point 4–6) groups by calculating CHADS2 score. Overall patients with low, intermediate and high score were divided into 1,395, 1,393 and 256 patients, respectively. In-hospital mortality among low, intermediate, and high score groups were 2.8%, 7.4% and 14.8%, respectively (P<0.001). The incidence of cardiovascular eventsamong low, intermediate, and high score groups were 7.8%, 16.3%, 29.3%, respectively (P<0.001). Kaplan-Meier analysis showed a significant difference between the groups (Figure). The event rates were significantly higher in both high score and intermediate score group than in low score group (P<0.001). Multivariate Cox hazard analysis identified CHADS2 score (per 1 point) as an independent predictor of cardiovascular events in addition to chronic kidney disease and lower body mass index. (hazard ratio, 1.344; 95% CI, 1.239–1.459; P<0.001). Among the factors constituting CHADS2 score, heart failure and age were identified as independent predictors for in-hospital mortality. With respect to the cardiovascular event during 3 years, heart failure, age, and previous stroke were revealed as significant independent predictors.

Conclusion

This large cohort study indicated that the CHADS2 score is useful for the prediction of in-hospital mortality and the cardiovascular events during 3-year follow up in Japanese AMI patients without atrial fibrillation.

P3406Validation of atherothrombotic risk score for secondary prevention in patients with acute myocardial infarction: the J-MINUET study

Background

Thrombolysis in Myocardial Infarction (TIMI) Risk Score for Secondary Prevention and CREDO-Kyoto Thrombotic Risk Score are contemporary secondary prevention risk scoring systems. However, these scoring systems have not been validated in other populations.

Purpose

The aim of this study was to validate of the TIMI Risk Score for Secondary Prevention and CREDO-Kyoto Thrombotic Risk Score in patients in the early phase of acute myocardial infarction (AMI).

Methods

The Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET) is a prospective multicenter registry conducted in 28 Japanese medical institutions. We enrolled 3,283 consecutive patients with AMI who were admitted to participating institutions within 48 hours of symptom onset between July 2012 and May 2014. Among them, 3,070 patients were included in this study after excluding 213 patients who died in the hospital. Clinical follow-up data were obtained up to 3 years. The primary endpoint was a composite of all-cause death, non-fatal MI and non-fatal stroke. The patients were stratified by the TIMI Risk Score for Secondary Prevention and CREDO-Kyoto Thrombotic Risk Score.

Results

At the 3-year follow-up, the primary endpoint had occurred in 337 patients (11.0%). All-cause death, non-fatal MI and non-fatal stroke had occurred in 177 (5.8%), 80 (2.6%) and 80 (2.6%) patients, respectively. TIMI Risk Score for Secondary Prevention and CREDO-Kyoto Thrombotic Risk Score showed a graded association with the composite of all-cause death, non-fatal MI and non-fatal stroke at 3 years in the J-MINUET population (Figure).

Validation of atherothrombotic risk

Conclusions

TIMI Risk Score for Secondary Prevention and CREDO-Kyoto Thrombotic Risk Score were shown to be applicable to the patients in the early phase of AMI.

Development of Duodenal Ulcers due to the Discontinuation of Proton Pump Inhibitors After the Induction of Sofosbuvir Plus Ledipasvir Therapy: A Report of Two Cases

Sofosbuvir plus ledipasvir (SOF-LDV) combination therapy is a promising therapy for post-transplant hepatitis C virus (HCV) reinfection. It is known that gastric pH elevation induces lower absorption of ledipasvir; therefore, the use of proton pump inhibitors (PPIs) should be considered regarding dose reduction after SOF-LDV therapy induction. Here, we report two patients who developed duodenal ulcers due to the discontinuation of PPIs after the induction of SOF-LDV therapy for post-transplant HCV reinfection. The first patient was a 71-year-old man who had undergone living donor liver transplantation due to HCV-related liver cirrhosis. Lansoprazole, 30 mg daily, was discontinued upon SOF-LDV therapy induction. Seven days after SOF-LDV therapy induction, gastrointestinal endoscopy revealed the presence of a duodenal ulcer. The second patient was a 54-year-old man who had undergone living donor liver transplantation due to HCV-related end-stage liver disease. Similar to the first patient, rabeprazole sodium was discontinued upon the induction of SOF-LDV therapy. Eighteen days after SOF-LDV therapy induction, gastrointestinal endoscopy revealed the presence of a duodenal ulcer. In both cases, these duodenal ulcers improved after the resumption of the administration of PPIs, and a sustained virologic response at 12 weeks was achieved by SOF-LDV therapy with PPI use. Thus, PPI use should be continued consistently during SOF-LDV therapy for post-transplant HCV reinfection.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and [Formula: see text] credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-[Formula: see text] requires at least three detectors of sensitivity within a factor of [Formula: see text] of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Pharmacological characterization of a novel potent, selective, and orally active phosphodiesterase 2A inhibitor, PDM-631

Recently, we identified a novel phosphodiesterase 2A (PDE2A) inhibitor, PDM-631 ((S)-3-cyclopropyl-6-methyl-1-(1-(4-(trifluoromethoxy)phenyl)propan-2-yl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one). PDM-631 showed potent inhibitory activities for human and rat PDE2A with IC₅₀ values of 1.5 and 4.2nM, respectively and more than 2000-fold selectivity against other phosphodiesterases. In rat studies, PDM-631 showed oral bioavailability and good brain penetration, and increased the cGMP levels in the cortex. These data indicate that PDM-631 is a potent, selective, orally active, and brain-penetrable PDE2A inhibitor. In behavioral studies using rat models, PDM-631 (3-30mg/kg) resulted in better discrimination between a novel object and a familiar one 48h after the acquisition phase in the novel object recognition test, thus indicating that PDM-631 increased object recognition memory. In contrast, PDM-631 did not attenuate the conditioned avoidance response at the same dose range (3-30mg/kg) in rats, indicating that PDM-631 did not show an antipsychotic-like effect. In test for extrapyramidal side effect, PDM-631 had no effect on catalepsy at the effective doses (10 and 30mg/kg) in the novel object recognition test, while haloperidol caused catalepsy at a dose of 3mg/kg. Our results suggest that PDM-631 is a good pharmacological tool that can be used to investigate the role of PDE2A and may have therapeutic potential for the treatment of cognitive impairments associated with schizophrenia and neurodegenerative disorders, without any extrapyramidal side effects.

Recurrent Hepatitis B and D Virus Infection in a Liver Transplant Recipient

Hepatitis B virus (HBV) and hepatitis delta virus (HDV) co-infections progress rapidly and lead to cirrhosis. In Japan, the prevalence of HBV and HDV co-infected patients is low. Therefore, there are few reports of patients with HBV and HDV co-infection having undergone liver transplantation. Herein, we report a rare case of recurrence of HBV and HDV in a 41-year-old man who underwent living donor liver transplantation 4 years prior.

MOB1-YAP1/TAZ-NKX2.1 axis controls bronchioalveolar cell differentiation, adhesion and tumour formation

Mps One Binder Kinase Activator (MOB)1A/1B are core components of the Hippo pathway. These proteins, which coactivate LArge Tumour Suppressor homologue kinases, are also tumour suppressors. To investigate MOB1A/B's roles in normal physiology and lung cancer, we generated doxycycline (Dox)-inducible, bronchioalveolar epithelium-specific, null mutations of MOB1A/B in mice (SPC-rtTA/(tetO)₇-Cre/Mob1a^flox/flox/Mob1b^-/-; termed luMob1DKO mice). Most mutants (70%) receiving Dox in utero (luMob1DKO (E6.5-18.5) mice) died of hypoxia within 1 h post-birth. Their alveolar epithelial cells showed increased proliferation, impaired YAP1/TAZ-dependent differentiation and decreased surfactant protein production, all features characteristic of human respiratory distress syndrome. Intriguingly, mutant mice that received Dox postnatally (luMob1DKO (P21-41) mice) did not develop spontaneous lung adenocarcinomas, and urethane treatment-induced lung tumour formation was decreased (rather than increased). Lungs of luMob1DKO (P21-41) mice exhibited increased detachment of bronchiolar epithelial cells and decreased numbers of the bronchioalveolar stem cells thought to initiate lung adenocarcinomas. YAP1/TAZ-NKX2.1-dependent expression of collagen XVII, a key hemidesmosome component, was also reduced. Thus, a MOB1-YAP1/TAZ-NKX2.1 axis is essential for normal lung homeostasis and expression of the collagen XVII protein necessary for alveolar stem cell maintenance in the lung niche.